Interview with Christoph Blase (ZKM)

Christoph Blase is working at the ZKM in Karlsruhe where he is running the Laboratory for Antique Video Systems. ZKM holds a unique position in the art world; it is an interdisciplinary research institution focusing on new media. Since its opening in 1997, the ZKM has become an important platform for the production and exhibition of contemporary art and emergent media technologies. Since 1999 the institute is led by the artist, curator and theoretician Peter Weibel.

Christoph Blase has been transferring video tapes and working with old video systems at ZKM since 2001. Recently he curated the touring exhibition "RECORD > AGAIN! - 40yearsvideoart.de – Part 2". Emanuel Lorrain (PACKED vzw) and Rony Vissers (PACKED vzw) met him in March 2010 in order to know more about Laboratory for Antique Video Systems and the management of ZKM’s large equipment collection.

PACKED: How did you start working in video and media art preservation?

Christoph Blase: In former times I had more or less nothing to do with any old televisions or video equipment. I had been working as an art critic for more than twenty years. Around 2001 I received a big video collection of tapes that were recorded at the documenta 51 of 1972. In that year my father took care of the audiovisual documentation of the documenta exhibition.

PACKED: How many tapes were there?

Christoph Blase: This collection consists of around eighty 1/4” Akai video tapes2. I tried to transfer them and to find some companies that could do this but I could not find any in Europe. The only one that I found was Vidipax3 in New York that still existed at that time. But organising a transfer by them was too complicated and too expensive. As a result I started to search for equipment myself. I found two or three old Akai video recorders of this system: Akai VT. I started here with a project in September 2001 to transfer these tapes to digital Betacam4 and from these digital Betacam tapes we made a compression with the Sonic compressor in MPEG-1,5 a very early format. Then we made a first exhibition in January 2002 or autumn 2001, I don’t remember.

This was the first time that I was really involved in this. After this experience and during this work I found out that there were a lot of videos of cultural interest: art videos, documentation about the art scene… These videos still existed, but what was no longer existing were the machines. There were already some conferences about all this audiovisual heritage that was on the verge of being lost. People were talking about it, but nobody was doing something. This is why I started on my own collecting old machines.

PACKED: And this is how you got your know-how about the obsolete tape formats and their playback equipment?

Christoph Blase: Yes, all the know-how I have today is something that I did not have in 2001. It really started at that moment. I had a little background coming from the video documentation that I did in the seventies. I also knew what open-reel machines and early cassette machines were, but my know-how stopped at the end of the seventies because from that moment on I was no longer involved with old videos. Of course I also saw a lot of video works in the seventies.

I started to collect all these old machine to get some knowledge about the systems. Every week I found a new system, a new machine. I started buying these machines on eBay, and my collection began to grow. At the beginning I bought the equipment for big amounts of money. For my first ¾” U-matic top-loader6 I paid 500 German Marks, which is 250 Euros. Today you could buy one like these for perhaps 20 Euros. I have bought my first open-reel machine, a Sony CV machine, for 200 Euros.

Then I had some luck and bought around 300 open reel tapes from a university in the south of Germany. They belonged to a language laboratory. The content of these tapes was not very important for cultural history, and this allowed me to try to get them running again without being afraid of damaging them.

PACKED: Is this how you started finding ways to restore old tape formats?

Christoph Blase: Yes, because the big problem was that all the 1/2” and other tapes were sticky7 and dirty. I developed several methods to make them run again. I tried to bake them.8 I did some tests to know how long I had to bake them, at what temperature, etc. I was fully aware that I would destroy a lot of tapes in order just to see what results one can get by baking them.

Then I bought an old film editing table. It still stands here in the lab. With this editing table I constructed a mechanical cleaning machine that allowed me to interact with it, to change the tape path and speed and to see how much of the dirt is wiped off. I called it the ‘Clean Putzer Version 0.7’ (laughs).

PACKED: When did you start working for ZKM?

Christoph Blase: When ZKM decided to fund the Laboratory for Antique Video Systems, I came with all my machines to this laboratory. This was in 2004. It was the starting point. First we were really busy in solving all the technical problems. How to digitise? What equipment to use to digitise? How to store this huge amount of data? And how to refurbish the machines? In the early times of the lab, I found a very good technician who is still working for us today. He has been repairing all these machines. Together we have developed some other machines and have constructed a second, third and a fourth generation of cleaning machines. Since approximately two years we have a very good technical infra-structure. In the meantime we have gathered more than five hundred machines. Today we can handle more than fifty different media formats from the middle of the sixties to the middle of the eighties. We have several machines for all important open-reel video formats. This enables us to change, to try out, and to find the best machine for each tape. We have at the moment for example five Sony CV open-reel machines9 running in one lab.

PACKED: But you also deal with more recent format than open reel video?

Christoph Blase: Yes, there is also another lab for the more modern formats. We have around five or six U-matic machines ready. This allows us to test which U-matic player is the best for one particular tape. We often have U-matic tapes that are running in a very bad way in a front loader machine, but when you put them in an old top loader machine you will get a very good result. Our strategy is to get as many different machines as possible in very good condition, and then for each tape try to find out which machine is the best.

PACKED: You told us that you use baking as a technique to restore the old tapes. What kind of baking oven and protocols do you use?

Christoph Blase: Based on my experience I know that it is very dangerous to say how you have to bake the tapes: how long, in which oven, at which temperature… This is very dangerous because in the baking process there is a certain point where you can damage or even destroy the tape. This is possible. It happened during my tests: some tapes got burnt. I don’t want to be held responsible for other people failures, and would prefer not to speak in detail about our baking procedures. If I would say “OK, we are working with this and this,” and someone else would try to build it again, the risk that he will destroy his tapes is very high if he has no experience. You need to have a certain amount of experience to bake your tapes.10

When I spoke with my colleague at the Sony restoration lab in France11 about the baking procedure, I asked him which temperature that they were using for baking. The funny thing is that the temperature that he told me that they were using was absolutely too low. It was clear for me that what he said was wrong because I can’t succeed with this temperature; it is impossible. But the temperature of 50 degrees Celsius that he told me is exactly the temperature of which you can say that nothing will happen. There will be no progress, but at the same time this temperature will also assure you that you will not destroy the videotape. 50°C is not enough to get proper results; it only guarantees that you are on the ‘safe side’. If someone bakes a videotape at 50°C, he probably will have to bake it for three days. You will not be able to destroy the tape, that’s for sure. But based on my experience 50°C will also not give you the effect that you would like to have. We use a higher temperature than 50°C for baking.

The audio community started with baking magnetic tapes. From them I have picked up some information on what is important and which degrees to use. Based on this information I have developed something and have made several tests in 2002. At a certain point I knew that my procedure was okay because we got our programmes running successfully. But today baking tapes is very rare at ZKM; we do perhaps one tape a month.

PACKED: Do you build up the temperature gradually during the process?

Christoph Blase: Yes, it starts at 20°C and it rises to more than 50°C. You keep it steady for a certain time and then you cool it down again. Of course you can’t take the warm videotape out of the oven and put it straight into the video player. We let it rest for at least one hour. The baking time depends, but it is at least six hours. After six hours you normally can see a result. You can say that for 70% or 80% of videotapes six hours is enough, but sometimes you have to bake a tape for twenty hours. We have had cases where we only got the results that we were looking for after twenty hours of baking.

PACKED: And then you have to proceed the transfer quickly because the effect doesn’t stay that long?

Christoph Blase: Some people indicate that you can only bake the tape one time and that then the effect disappears. This is silly. I had a videotape that was baked and that after baking was checked to find out if we could run it because we didn’t have time to transfer the tape immediately; when we saw that the was OK, we decided to transfer it the next week. Then we forgot about it and after two months we realised that the baked tape still needed to be transferred. By then it got sticky again and we had to bake it again. This was no problem, it worked. Subsequently we transferred it immediately. We also have had tapes that were baked a second time three years after the first baking; we wanted a certain sequence and needed absolute perfect quality. This tape was after it was baked three years ago already immediately running perfect, without any problem. These are two examples, We have videotapes that will be sticky again in six weeks after baking and that will have to be baked again, but of others I am sure that at least four weeks after baking, you can still transfer them as many times as you want. It can be completely different from one tape to another.

PACKED: But the baking process is always used in combination with cleaning?

Christoph Blase: Yes, we always start with the cleaning first. Because baking is still a risk, we only bake if the cleaning does not give us the result that we wanted. Our cleaning machine is able to run both very slow and very fast.

PACKED: Some television archives also use in some cases the baking process to skip the time-consuming cleaning process.

Christoph Blase: Maybe this is possible when you have 1” or 2” videotape. But there is also another thing. When you bake the tape you just have to put it in the oven and you can do something else during the baking process. But when you are working with the cleaning machine, you have to be there during the whole process. It is not an automated process and you have to look at what you are doing, and you have to make continuously decisions while you are in front of the machines.

PACKED: Once the videotapes are digitised, they go back to your storage space. In which conditions are the tapes stored?

Christoph Blase: Normally we maintain climate conditions between 15°C and 20°C and a low humidity. This is another interesting experience. We receive videotapes that have been stored in different kinds of storage conditions, On the one hand we receive for example videotapes from museum storage spaces with perfect climate control. These tapes sometimes have been in their storage space for thirty years. With a collection of twenty tapes, it might happen that let’s say the first three are immediately running perfectly without any problem, that the next five are catastrophic and that you will have to work on them a lot, and then that the next two tapes are running perfectly again. Although all these tapes stem from the same period, the same week and the same manufacturer, they behave very individual. Each tape seem to have its personal evolution. On the other hand we also receive tapes which were during thirty years stored under a roof with temperatures below zero in winter and with 40° C in summer, and the result is similar to the tapes stored in good storing conditions: some of them are running and other ones are not. In general, 80% of the open-reel tapes that arrive here are not running but 20% are. You never know which one will run. The degree of problems that we encounter during the cleaning process is also very different.

Our experience is that the condition of the tapes is - of course - a little bit better when they come from museum storage spaces than from under a roof. But the point is that there is absolutely no warranty. The only thing you can say is that Scotch tapes from the seventies make less problems than the Sony tapes. But the pity is that Scotch tapes were cheaper at the time, and if the people thought that they had to record something very important they bought the more expensive Sony tapes. Sony was already very early aware that they were not producing the best tapes and this is why they offered certain solutions: they constructed cleaning machines by themselves and offered the possibility to use these machines for a certain period if you would buy a U-matic system, transfer everything to U-matic tape and destroy your old open-reels.

We tell everybody “never throw away the old material, even if your old tapes are transferred and digitised and you have the impression that the results are good”, because you never know what possibilities the future will bring. We have for example certain very important tapes that we have transferred three or four times during the years. We continuously stumble upon new solutions that could have a better effect on the original tape, and then we try something different than what we did the first time.

PACKED: And what capture board are you using for the digitisation?

Christoph Blase: We use the Io from Aja Video Systems.12 We use the Quicktime container format13 and the codec14 that comes with the Io devices. We digitise the videotapes to an uncompressed file.15

PACKED: We know that you have been using the Diamant software16 at ZKM. What is your experience with the restoration software?

Christoph Blase: The project ‘40yearsvideoart.de – Part 1’ used the Diamant Software. I saw it and I also was in the Diamant workshop. Our experience is that it is maybe a good restoration software for film, but not for video.

PACKED: Does this mean that you are only working frame by frame with Final Cut,17 and that there is no automation involved?

Christoph Blase: Yes, there is no restoration software for the drop-outs or things like that. Consequently we try to solve the drop-out problems and the others before the tape is digitised; unless it has always been there. What you often have is a recorded dropout because the tape is a copy from an earlier generation tape. In this case there is nothing you can do. But for some tapes that are very important we do it by hand, it is like ‘colourising’ in a way (laughs).

But we really try to avoid the restoration by putting all our efforts in the cleaning of the tape and the digitisation. When we know from the beginning that it is a very important tape, we will make the efforts to make the first digitisation the most perfect one. When we are not sure of the content – and often this is the case – we will make a kind of viewing copy and after this we will decide whether it is really worth the effort. We will then digitise it again in the best quality that we are able to achieve. Only if necessary, we will restore it in a digital way. This is the usual process.

PACKED: How do you store the files then?

Christoph Blase: We have stored everything on LTO-318 with a back-up in several places. Everything is backed up. Until now we have only had great experience with LTO, especially when we needed to go back to the so-called ‘digital masters’. Each month we have consult two or three times our digital masters that are on the LTO-tapes. If it is not clear what somebody exactly needs, we will play it from the digital master that comes from LTO and will than make for instance a digital Betacam copy from the computer. This means that we accidently control our files on the LTO-tapes, and until now there has never been a problem. If there would be a problem, we would of course immediately check the copy. Perhaps in 5, 10 or 15 years time, there will be problems that no one knows about today. Since we consult the LTO tapes every month, I just hope that we will get aware of the problems early enough.

PACKED: For how many years have you been working like with the LTO tapes?

Christoph Blase: Three years at least. I think that it will be four years this year.

PACKED: Do you also create any viewing files?

Christoph Blase: Yes, of course we create an MPEG file19. 99% of the copies that go out are made from the MPEG files.

PACKED: What is the status of the Laboratory for Antique Video Systems within ZKM?

Christoph Blase: At the beginning we were part of the Institute of Visual Media here at ZKM, After one or two years and some internal reorganisation, we became a department on our own within ZKM. We were merged with the audiovisual archive of the Media Library. All workflows were changed to assure that every department within ZKM responsible for digitisation is now working in the same way: with the same workflow, the same description models for the server, etc. The aim was to make sure that the results of the work done within the different departments can be combined very fast.

Of course it can never be perfect. Even if a machine for a very rare format was still running wonderfully two years ago, you cannot be sure that it will be running if you would take it out of the storage room now, and then start it. Sometimes when we have to transfer a rare format, we need two or three days to repair the machine that we want to use for it, or even that we need to find another machine. In the meantime we have built an archive of thousands of videos that can be easily accessed in order to produce in about ten minutes for instance a DVD for viewing purposes or to generate a file on a flash card for use in exhibitions.

After our infrastructure was set up and was more or less working perfectly, we started to get more involved in the content of the videotapes. This is in the end the reason why we do all of this. Someone once said that I am a ‘hardware junkie’, but in fact I am a ‘software junkie’. I am interested in the videotapes and not in the machines. Of course I like the machines, but I got involved with the hardware just because there was no way to get all these old videotapes visible and accessible again without the machines.

PACKED: And this was the aim of the exhibition ‘RECORD > AGAIN! - 40yearsvideoart.de – Part 2’?

Christoph Blase: Yes, ‘RECORD > AGAIN! - 40yearsvideoart.de – Part 2’ is a big touring exhibition funded by the Kulturstiftung des Bundes and with a big exhibition catalogue of almost 500 pages that we are currently preparing. The occasion of this exhibition is what really got us started to search for videotapes. We went to the Netherlands Media Art Institute – Montevideo / Time Based Arts20 and all the other institutes and museums that collected tapes very early in the seventies and in the eighties. We also got in contact with a lot of older artists and a great majority of them still had their tapes. In the case of for example Ulrike Rosenbach,21 we have found a tape from 1978 that had more or less never been shown. It is one of her best videoworks, but at the time nobody wanted to show this tape. We have restored it and have made a better version from the original ¾” U-matic tape that she had.

Thus we are now looking to find interesting material. We have collected a lot of archives. Although we often know what the archives contain, they are not well documented. We must proceed to document them and to make them available for scientific research. This is the next step in the work of our lab.

PACKED: Can you tell us something about the equipment related to the videoworks?

Christoph Blase: Three years ago the decision was taken that for the exhibition ‘RECORD > AGAIN! - 40yearsvideoart.de – Part 2’ most of the old videoworks would be shown on devices, monitors, television sets, etc from the period in which the works were created. As a result I started to collect all these Wega, Braun, Brionvega22 and old Sony monitors that we afterwards refurbished. Today we are able to show a work with eight Wegavision monitors side by side in line, displaying the video material on very good old black and white CRT monitors.

PACKED: You collected a lot of televisions and monitors in order to be able to do this. Can you tell us through which channels you get all the equipment?

Christoph Blase: There is one main channel: eBay. Without eBay it would be impossible to gather so many equipment; it is a major source. Since last year we more or less stopped buying equipment. We now only do it when the equipment that we find is very rare or when we do not already have it, or just one or two items of it. We have enough equipment at the moment. But without eBay it would not have been possible to build up a lab like this. 70-80 % of the equipment that we hold has been bought through eBay.

PACKED: What are the other channels?

Christoph Blase: Today we also get a lot of donations but it is rare that we are donated an open-reel machine. Most of the time receive ¾” U-matic players and also a lot of monitors. We even get donations of old television sets. Lately it even has become too much. We sometimes have to refuse things because makes no sense for ZKM to take in every old Grundig or Neckermann television set. Sometimes we also get offers to buy things, for instance from someone who had a video studio or a company for video production and who is now retiring. As the price of equipment was hundreds of thousands of Euros when they bought it, they sometimes think that it is still worth 50.000 Euros - but most of the time it is not even worth 5.000 Euros. It is very difficult to explain to some old people that what they have has not much value today. We will only buy it if it is something very interesting for us.

Other sources are the artists and the museums from whom we sometimes get the original equipment. We have received all kinds of original equipment from Wolf Kahlen,23 the artists group Telewissen,24 from Ulrike Rosenbach, etc. that was used by them at the time. These machines are ‘museum pieces’ and we do not work with them. We just keep them as ‘the artist's equipment’; it is another category of machines because they are the original machines that these artists worked with.

PACKED: How many categories are there?

Christoph Blase: First we have a collection of videotape and videocassette recorders that can be used to make transfers. A part of this collection is refurbished; these machines are our ’working horses‘. Furthermore we also have a collection of machines for spare parts or equipment that is meant to be refurbished in the future. Then, as I mentioned earlier, we have a collection of machines that are not part of the workflow. These are the machines that are coming from some museum and that are just meant to be shown as an ’original machine‘ during shows, exhibitions, etc. On top of this we also have a collection of television sets to display and to present the content of the videotapes. We have a big collection of several different types of colour monitors and colour television sets. We also have a lot of black and white television sets. We should also not forget the digital hardware that we have. This is very important. Some machines are in between, like the very important group of the cleaning machines. We have cleaning machines for ¼”, 1/2” and 1” tapes, for cassette formats as ¾” U-matic and also VHS. We have around six or seven cleaning machines; some of them are of course RTI machines.25

PACKED: With regard to the equipment that you use in the exhibitions, you only mention the televisions. Does this mean that you never use original playback machines in exhibitions?

Christoph Blase: Yes, it makes no sense for us to do this.

PACKED: Even if they are a visual part of the installation?

Christoph Blase: There are some examples in the exhibition ‘RECORD > AGAIN! - 40yearsvideoart.de – Part 2’. We made for instance a reconstruction of a certain video installation from 1981, with a table on which a U-matic player and a colour TV are placed. As part of this work we did put an original U-matic top loader on display, but it is not playing.

PACKED: Does this mean that you used a flash card player instead?

Christoph Blase: Yes, we used a flash card player. We stopped using DVD players one or two years ago and moved to flash card players. All videos that we show in the exhibition ‘RECORD > AGAIN! - 40yearsvideoart.de – Part 2’ come from the digital master that we have made. From these masters we have also made compressed MPEG files that we have put on a flash card player from which the they are being played. Of course this is an in-between situation because on the old black and white TVs for example you normally only have the old antenna signal, but we have sold these problems.

PACKED: You never use the original equipment to show a work?

Christoph Blase: Yes, we never do it. I think that if you would like to try it, it would be very difficult. We had for instance an installation with a sound recorder that was running a one-hour tape. Every hour the museum staff had to rewind the tape and press ‘play’ again, what is not practical and too time-consuming for a museum team. Just imagine that you would have to do this for twenty or thirty works… In the exhibition we already have around sixty television sets to turn on and off.

The original 1/2” machines were also not constructed for exhibition use. We have to keep in mind that the video exhibitions, experiments, festivals, workshops, etc., or whatever they were named in the seventies, were not events that lasted for weeks; they lasted for only a few days. The technicians or the artists - the people who knew how to handle an open-reel video recorder - were present. Today nobody has this knowledge in a museum. It has become more or less impossible to show a work with these types of equipment. You would surely also more or less destroy your equipment and your tapes. You would definitely have to make a new copy of the original tape on a 1/2” tape. This copy would be destroyed during the exhibition, simply because this tape format was not developed to run continuously for weeks. This became only feasible with the ¾” U-matic technology, but even there it was - and still is - problematic. Johannes Gfeller26 did it in the exhibition ’Reconstructing Swiss Video Art from the 1970s and 1980s’.27 In a certain way it worked well, but he had to change some U-matic players. He had also made several copies of every videocassette and changed them during the exhibition. They became worn out after a while.

PACKED: Do you take the limited lifetime of the televisions and the monitors into account during an exhibition?

Christoph Blase: Yes, we do. The exhibition ‘RECORD > AGAIN! - 40yearsvideoart.de – Part 2’ started here in Karlsruhe and lasted for six to seven weeks, went afterwards to Aachen for around eight weeks, then to Dresden for nine weeks in and is now in Oldenburg.28 At every location where the exhibition was shown, we only had one device that had a failure. That one we had to repair. As there are more than sixty pieces in the exhibition, this is a very good result.

All these television sets had to be refurbished because you cannot immediately put them on display in an exhibition if you only got them the day before. I received for instance a Wegavision last weekend; even though I saw that it was running when I bought it, you could not use it for an exhibition right at that moment. Perhaps it will work for one or two days or something like that, but then it will fail and get damaged.

After the refurbishing when all Elcos29 and capacitors30 get changed and some other servicing works – this always depends from one television set to another – they stand here in our video showroom where we keep them running for three days. If they successfully run for three days, I can almost be sure that it is possible to send them to an exhibition that runs for weeks in a row. In these three days 70% of the equipment will have no problem. 25 to 30% will have some problems and break down, either in the first half a day or in the last half a day. In this case we will have to repair them again. Most of the time it is just some little detail that needs to be fixed. Most of the time the machinery is running again after twenty minutes, and will keep running for three days in a row. My experience is that if a television set is running for three days, it will probably run for several weeks.

PACKED: What is the worst thing that can happen to a television set or a monitor?

Christoph Blase: The worst thing is if the so-called THT31 gets broken. If you do not have another one from the exact same model, you are in trouble.

PACKED: In this case you would have to change the whole CRT tube?

Christoph Blase: No, we change the THT. But sometimes we change the CRT tube too. It depends which part is broken. It might also happen that we have to change the power supply unit. Sometimes they have a very special power supply unit. We already had some machines here with a broken power supply unit, and unfortunately we didn’t have any of these. We even couldn’t get any. As a result we had to wait until a television of the same model came on the market in order to buy it again. Here in the storage space of our lab we have a very special television model with a big colour monitor and underneath a row of three little black and white monitors. To get this television running we had to buy three. It is in the exhibition now.

PACKED: When you buy a monitor or a player, do you buy them with a special work in mind? Or do you just try to have enough equipment of a certain period to be able to play different kind of works?

Christoph Blase: It depends. Sometimes I do have a work in mind and then I buy the equipment because I think that it would perfectly fit the work. Or I have a work that was already shown in a certain way and I think that it would perhaps be better to show it on another television set instead. We have made a reconstruction of the work ‘Schafe’ (1976) of Wolf Kahlen and for this we needed six identical little black and white monitors of the seventies. They were not easy to find. This type of monitor had no devices on the front and you could only see the cathode ray tube; this was one of the purchase conditions. The other condition was that it would have a seventies-look but that this should be not too dominant either.

PACKED: What are the other cases where the CRT type is very important for the work?

Christoph Blase: You have early videoworks where the artist is working with the television screen itself. The artist appears on the screen and it looks like if he is inside the television and that he is doing something on the glass – from the inside from the television to the outside, to the public. In the seventies you had these televisions with round edges and corners. To show this kind of early videoworks you need of course a television set with round corners; you cannot show them on a flat screen or on a modern Bang and Olufsen television32. What you need is a black and white television with these round shapes; this is very important.

PACKED: When ZKM acquires a work, does it always acquire the equipment together with the work?

Christoph Blase: This is not possible for old video works. For new works we always acquire the equipment as well as the documentation and the source code, if there is any. If ZKM acquires a contemporary videowork, it will also ask for a digital Betacam or sometimes for the Final Cut source project file but never for a DVD.

PACKED: Does ZKM also buy spare equipment at the same time?

Christoph Blase: It happens. At the moment we have a big exhibition at the ZKM with refurbished works of the last twenty years of ZKM. In the meantime a lot of old tube monitors - especially colour SONY monitors - are being purchased. We are also looking for special models. Of course we have some Nam June Paik video sculptures and we know exactly which television and monitor models that we need to look for. Yes, we buy spare equipment but this only started one year ago.

PACKED: This is mostly for works that are using already obsolete technology. But let us imagine that the ZKM would purchase a recent work by for instance Bill Viola with a series of plasma screens. Would the policy of the museum be to buy spare parts at the same time for this kind of work?

Christoph Blase: If somebody is thinking about this at that moment, yes (laughs). I see what you mean but the awareness about this problem only arose during the last few years; before nobody thought about it. Since the founding of the Laboratory for Antique Video Systems and the rise of the problems to show media artworks, the curators at ZKM have started to realise that the problem does not only exist for the real old videoworks but also for the in-house equipment. Depending on the works they now try to have for example two or three spare monitors, more flat screens, more monitors of a specific model, etc. When it concerns very recent equipment, they will try to wait until the prices go down. They will try to buy it when there is a stock of certain models on the market for a third of the price of two years ago.

Incandescent light bulbs are another example. It has become forbidden to produce incandescent light bulbs in the European community but our technicians have found a company that still produces these incandescent light bulbs. This company is allowed to produce a certain amount of them. As a result we now have a source. We have some works with these incandescent light bulbs, and you cannot replace them by the more energy-efficient lamps. We now have created a collection of hundreds of incandescent light bulbs for the next ten years. We think of these problems.

PACKED: This is a problem that is similar to the one that arose for the works of Dan Flavin.33

Christoph Blase: Yes, for the works with the tube lights. But I think that for the Flavin works they already bought the tube lights ten years ago. The problem already came up at that time. They have a big collection of tube lights too.

PACKED: When another institution borrows a work for an exhibition from the ZKM collection, do they also borrow the equipment from ZKM to show the work? For example when it concerns an old videowork with old CRT monitors?

Christoph Blase: Different situations are possible. It depends on the work. If they would for instance borrow a small video installation of Nam June Paik, they would of course get the entire set.

PACKED: Because the equipment is so specific... Did you provide the equipment for every instalment of the ‘RECORD > AGAIN! - 40yearsvideoart.de – Part 2’ exhibition?

Christoph Blase: Yes, and this also meant that we had to transport the television sets. There is an exhibition upcoming where a museum wants to show some installations from our big ‘RECORD > AGAIN! - 40yearsvideoart.de – Part 2’ exhibition. They will need the original equipment, and they will get it from us.

PACKED: Do you have a special warehouse to store the equipment?

Christoph Blase: In the past there were several rooms available in the ZKM building to store our things, but after a year we were asked to leave these spaces (laughs). ZKM also has a very big warehouse at another location in Karlsruhe where we can put the things that do not need to be here all the time. Within the ZKM building itself we recently got a room on the fourth floor under the roof where we can put some stacking pallets with stuff that we do not want to be in this outside warehouse because we do not know whether we would suddenly need it.

PACKED: What are the storage conditions in the warehouse? Is the equipment stored on shelves?

Christoph Blase: The warehouse belonged to an old printing company. It is the space where the paper was stored. The conditions are very good there: not humid and more or less cold. The different devices are on stacking pallets on big ten meter wide shelves. You have to go there with a forklift truck. This is why we all had to get a license for this (laughs).

PACKED: Do you provide maintenance for the equipment in the case of long-term storage?

Christoph Blase: We try to have a certain rotation of our main equipment in the lab, of the old open-reel 1/2” machines for example. When one machine has been used in lab for half a year because it was our favourite, we will try to replace it by another one. We will take this machine from our storage space beside our lab, and then use it for a few months. In this way every functioning machine, or every refurbished and functioning machine, runs at least one week a year. In reality it happens that we forget to use a machine or just do not use it because we do not need it. We recently pulled out an NTSC machine34 that had not been running for two years. It was playing, but the belt for the rewind and fast forward actions was broken - but all in all it was still running. We were able to use the machine to work on the transfer of a specific videotape, but we had to rewind the tape on another machine.

PACKED: This mainly concerns the video players, but do you also have a similar strategy for the television and monitors?

Christoph Blase: No, we don’t have at the moment because almost every very good piece is running in exhibitions. It is not necessary to have a similar strategy for our monitors.

PACKED: Do you also collect spare parts like belts, or redesign parts sometimes?

Christoph Blase: We use every possibility that we can; we do it all. Often you get ’new old stuff’ from companies that provide spare parts. These refurbished parts are sometimes good, but sometimes also really bad.

PACKED: Is all equipment catalogued somewhere in a database?

Christoph Blase: I have a Filemaker database for use in the lab only, and the equipment is marked ’refurbished‘ or ’not refurbished‘. If I am looking for a certain very rare format, I will use this database to find the specific machine that has a specific number.

PACKED: Do you store the equipment together with other parts of the installations, for instance a sculpture or a sculptural element?

Christoph Blase: Yes, normally they are all together. It is not divided into for example ‘stone’ and ‘electronics’.

PACKED: Where do you keep the service and user manuals?

Christoph Blase: A documentation database of the big collection of the ZKM exists, but our lab is not involved in this. It depends where we keep the manuals. Some documentation is stored with the rest of the documentation of the works; some others are here in the lab.

PACKED: When you put monitors on the stacking pallets do you wrap them in plastic or put them in cardboard boxes?

Christoph Blase: It depends on the size. Sometimes we wrap them in plastic. We also have these big cardboard boxes called ’Panzer Karton’. Sometimes we put them in there and seal them. It depends on the purpose and the category of equipment. If it concerns a long-term storage, a television for spare parts or a television worth several thousands of Euros, the storage and wrapping procedure can be completely different. It goes from equipment standing unprotected somewhere in the ZKM building, to equipment standing here in our storage space beside the lab, to equipment stored in our warehouse...

All of the most important pieces are here in the storage space at ZKM. In the warehouse we only have things that we do not need at the moment. We know what is in the warehouse because we sometimes go there and have a look. We have a big collection of old television sets that we have bought a few years ago. These are mostly television sets of the fifties that we do not need at the moment, but I am sure that we will need them one day. They are currently stored in our warehouse.

PACKED: The equipment that is stored in the warehouse does not get a regular maintenance but the equipment that is used in the Laboratory for Antique Video Systems does. What kind of maintenance do you provide?

Christoph Blase: The little bottle of isopropyl alcohol35 is used every day in our lab. Cleaning is the only regular maintenance that we do ourselves. When we see that a piece of equipment is experiencing problems, we give it to our technician who will provide further servicing.

PACKED: Do you sometimes use external servicing?

Christoph Blase: There is no external service, that is the problem. This is why our technician normally does all the servicing. Even if we could bring modern Sony monitors of the nineties to Sony for repair and maintenance, it would be very expensive. When our technician has to repair a monitor of a certain model, he will use this occasion to service at the same time the other monitors that we have of the same model. This is the way how our technician works.

PACKED: What do you consider as the most problematic equipment in terms of acquiring, purchasing, repair and maintenance?

Christoph Blase: The problem now is that you can not buy new CRT monitors anymore. Hantarex was a very classic monitor to buy until two or three years ago. If you would try to buy a new Hantarex36 monitor today, you would have to struggle a lot. The video wall of Hantarex monitors is not available anymore because they stopped the production. A few weeks ago I made a research and I found out that they had only about twenty-one pieces left in the stock.37

In ten years there will be a problem with CRT monitors. At the moment it is not really a problem yet because there are still enough second-hand monitors on the market. We already buy and collect hundreds of monitors for everything and for every possibility. The prices of the monitors are still OK; they are not that high but they will rise over the next ten years. If they are still functioning they will probably cost by that time ten times their original price. Until now I can still find it if I am looking for something. This is my impression. I could be wrong because I am not spending that much time anymore on looking for equipment on eBay. But I guess equipment for ½” videotapes are maybe becoming rarer now.

PACKED: Do you collect equipment for your own personal collection or for the collection of the ZKM?

Christoph Blase: Both. All donations are going to the ZKM collection and I buy machines for the ZKM too. Furthermore I still buy once in a while television sets like the Brionvega for my own collection. There was no equipment in the ZKM at the beginning. Bringing in my collection in order to start the Laboratory for Antique Video Systems was a part of my contract when I started working here.

PACKED: Does the contract also allow you to store your personal collection here and to have it maintained?

Christoph Blase: Yes, because we also work with my equipment. The equipment is refurbished, but it also has a certain lifetime that is spent in presentations and exhibitions.

PACKED: In this way the ZKM could avoid to start from scratch?

Christoph Blase: Yes, I came in with a certain stock. I had it all here and I could use any specific machine when I needed it. I think that my first contract with ZKM mentioned something like one hundred machines.

PACKED: Do you also have to deal with devices like cameras?

Christoph Blase: Our technician has the knowledge to deal with it. We can repair and maintain cameras. This is not a problem, but you only need a camera for very specific works like closed circuit installations. For example I need a camera here in the workshop when I reconstruct the Dan Graham38 piece ‘Time Lapse Machine’ with my students. In this work you have one recording machine and another one two meters beside it that is displaying your picture with a delay of about ten seconds. In this case we need a camera, yes.

PACKED: Do the artists get involved when one of their works is reinstalled at ZKM?

Christoph Blase: Of course, the artists get involved. We always make several proposals and then the artist can say how he prefers his work to be installed. We had an interesting case with a work from the former DDR.39 The work was a performance and in this performance there was a small monitor on a stage, running another video.40 The monitor was a model from the DDR and we had the exact same model from the DDR: not in white like it was in the original setting, but in red. Do not ask me why, but the artist said: “Never red, never red monitors, I never want to see my video on a red monitor !!” (laughs) In the end we gave him a totally different monitor.

PACKED: Do you collaborate with other institutions and collection holders?

Christoph Blase: Yes, we are restoring and digitising old video tapes from other collections. This is how we collaborate. We received for example 500 tapes of the Raindance Corporation41, the Radical Software42 and the VideoFreex43, all from the MOMA in New York. This collection is here since December 2009. They asked us because they could not figure out a possibility to transfer this collection of videotapes.

PACKED: There are several contemporary art museums in Germany and in other European countries that probably also hold videoworks for which they have to find preservation solutions...

Christoph Blase: Yes, and our offer for these museums is very good. They just have to send us the original tapes that they have. We will restore them and create a digital master. When the process is finished the museums get back everything they want: the tapes and an uncompressed digital master on a hard disk, if that is what they want. All we ask in exchange is that we are allowed to keep a copy of the digital master for our scientific collection that grows in this way. We do not acquire the rights to show these works publicly. The institutions are getting their tapes transferred without having to pay anything for it.

Usually artists, collections and museums are very happy with this deal. But since one and a half years the other part of the agreement is also that I am no longer able to give any specific date indication on when the transfer can be done. Sometimes they will have to wait for months and years, and sometimes it can be done very fast. But we are not able to answer a request of a museum that would say "we have here twenty open-reel tapes and we need them digitised in two weeks." If we would accept this we would no longer be able to perform our own work. We have built up this infrastructure, we have the technical infrastructure and the manpower to do this kind of jobs but we already have our hands full with our own projects.

The other thing is that when you start providing this kind of preservation services to other institutions, you often have to deal with restorers and museum people. All of them will be more or less aware and will have a certain degree of knowledge about the different problems involved. This means that there will be a lot of conversation and communication time dedicated to giving them explanations. Of course I explain these kinds of things to my students, but I can’t explain to every curator during two and a half hours why we do stuff in this way and not in another. We do not have the time to document which part we have changed in a television or a video player. It makes no sense. It is just a lot of paperwork. I know that a lot of people are very proud of this kind of paperwork but it means more or less nothing. What we are interested in is running the equipment.

PACKED: Do you have students coming here?

Christoph Blase: Yes, students from the Academy in Stuttgart, in Germany it is called ‘Studiengang Konservierung Neuer Medien und Digitaler Information’44. It is the restoration of media art and the courses concern media restoration. They come here every semester for three days. I teach them about carrier formats: which ones have existed, what carrier format was developed when, who uses what, what are the positive and the negative aspects of certain developments of certain recording and playback equipment, etc. And I also teach what is typical for an old black and white video. Together we produce a black and white video in order to give them a feeling of the problems, with the camera. In the second part they learn how to restore videotapes, they work on the cleaning machine and they take care of the videotapes. The third and fourth part are the actual digitisation: how to handle the digitisation? how to store the data? and what is going on with the digital data files. This is in short what the study program is about. How to handle the process? How to store and what is going on with all the digital data files.

PACKED: You talked about exhibition strategies for this kind of work. Has ZKM in some cases decided to show the documentation about the work in an exhibition instead of the work itself?

Christoph Blase: I can imagine that this could happen for scientific research. For instance in our ‘RECORD > AGAIN! - 40yearsvideoart.de – Part 2’ exhibition, we had a six-channel work45 and beside it we displayed the documentation of the presentation in 1975.

PACKED: It was shown in combination?

Christoph Blase: Yes, we showed it in combination and it looked absolutely different, but it was the same work.

PACKED: Nowadays museums are open from 10 o’clock in the morning until 6 or 7 o’ clock in the evening. This is not problematic if you have a painting or a photograph hanging on a wall, but is it a good way to show these early videoworks that are characterised by the use of complex – now obsolete - equipment that has only a limited lifetime? They were also shown in a completely different way in the 60’s or 70’s.

Christoph Blase: One example is the work ‘Der Magische Spiegel’46 by Telewissen. We had it in the ZKM exhibition for two years, running more or less every exhibition day. We had the original version from December 1970 that was running on a Wega monitor. We only had to change this Wega monitor one time in two years.

PACKED: Did you ever change the way of exhibiting a work because of the limited lifetime of the equipment?

Christoph Blase: Currently we have had no problem with this. Our policy was the same for every place where the exhibition ‘RECORD > AGAIN! - 40yearsvideoart.de – Part 2’ has been shown: if a monitor breaks down, we will install another one. At every exhibition place we had four or five spare monitors. If one broke down, we would take the next one. For the six-channel work with the six b/w monitors, we did send seven identical ones. Thus there was always one available for replacement if necessary. At one moment one of the monitors did break, and it took no longer than ten minutes to replace it and make the installation run again. For such big exhibitions you have to provide a certain amount of spare television sets that can be used in case one television set breaks down during the exhibition.

The Braun television from 1959 was for example very weak. We knew this when we used it for the exhibition in Aachen. As a result we decided not to use it during the next exhibition in Dresden, but we used another one that was ready. We have a certain amount of equipment that fail. In Aachen it was that Braun television, in Dresden it was a Bang & Olufsen and in Karlsruhe it was one of the JVC VideoSphere Ball Nivico televisions.

PACKED: Was it a problem of capacitors?

Christoph Blase: For this Braun television it was. This was one of our earliest television sets. As a result we did not yet have much experience nor spare parts or components. In the meantime we have got the spare parts and components from our warehouse. After one hour of repair this Braun television was running again. Although we did not expect it, it was not a very big surprise that it failed during the exhibition tour. At the moment we have a very bad Braun in the exhibition that will be replaced by another Wega in the next couple of days. We already knew at the beginning that this television set would only work for one or two months, but we had no time to refurbish it completely and perfectly.

PACKED: Since you started working on these ‘40yearsvideoart.de’ projects you have digitised a lot of German video works. Do you have any idea of the proportion of what you have digitised in relation to the total amount of the works that are worth to be preserved?

Christoph Blase: Yes, this is another special problem. We have digitised hundreds of videotapes for projects and exhibitions. I am sure that if we would digitise another one hundred tapes and look at them carefully in combination the other few hundred that we have, we could present at least one more exhibition with completely different works that are equally good to the ones that have already been shown and that would make an interesting exhibition too. I even think that we can do two or three exhibitions with the material that we have.

We still find interesting works in collections. Sometimes we find a work in the archive of an artist that he had forgotten about and suddenly this work appears to be very interesting, Maybe it already was a very important work in the period when it was produced but everyone forgot about it. It also happens that an artist points us out an important works. But then when he looks at it again, he finds out that it is no longer that interesting. His memory failed because the last time that he had seen the work was already thirty years ago.

It requires a lot of research in order to find out which videotapes contain interesting works and which not. These are the next steps here in the lab. We have to develop a system based on database that will make it possible to view the videos for scientific research. Technically speaking this is very easy. I think that we will start working on this soon, We have hundreds, if not thousands of videos that are currently not available for scientific research.

We will still do all the other things too, but we have to find a solution to make the video works accessible. The access to all these works is a big problem. As I already told you I think that there is a lot of material which could be very interesting in this context.

PACKED: And then it is a matter of deciding what is of importance and what is of less importance?

Christoph Blase: Yes, therefore I would like to have it available for scientific researchers, in order to make it possible that everybody can go there and look at the material.

PACKED: Did you make a first selection of what is worth to be digitised and what is not worth before you actually started digitising?

Christoph Blase: Yes, but in the case of - for example - the open reels we still have to digitise everything. Otherwise we won’t be able to look at it. Every tape gets cleaned. When it runs through the video player, it gets digitised at the same time - although not always in the best quality. Sometimes it gets digitised in a lower quality because we do not know whether it is really worth being digitised, whether it is something that is important for our heritage or whether it is something that we can forget about. This is of course the first step.

We see so many works during the year, every week and every month, that we sometimes also forget works. We need to be systematic but cannot look at everything. Other people also have different points of view. Thus we have to find ways to make it possible that people who are interested can sit here somewhere in the house to watch hours of videoworks. I want to them to be able to do this if they are interested in a certain project, an exhibition or certain cases and so on. This is very important in order to be able to learn more than we have done until now.

PACKED: You will set up some kind of viewing platform?

Christoph Blase: Technically speaking setting up a viewing platform is not difficult. The problem is the documentation of all this material. Take for example this Raindance Corporation collection. It consists of 500 U-matic and open reel tapes. Some of them are very complicated formats: open-reel loop cassettes, very rare things and not easy to handle. I am sure that within this collection there are one or more treasures to be found: really forgotten things. But I will not exactly know what the treasures are until we have digitised the whole collection. Of course we have made a first selection. We have a list, and we sometimes contact the artist Ira Schneider47 who can tell us what is important and what is not. But our experience is that the memory of the artist might fail. These early video artists are not the youngest anymore and their memories are sometimes not the best. This is very normal.

PACKED: And the perception of the work might also have changed during the years?

Christoph Blase: Yes. this is very important.

PACKED: Do you work with the artworks because they still have some importance today or because they were important during the historical period when they were produced, for instance during the seventies?

Christoph Blase: The selection is a decision that we make in our projects but it should also be possible for other curators, or scientist to make this decision, with completely different connections. Of course there are people who see totally different aspects in our videoworks than we do and who could use the works in contexts that we did not think about.

PACKED: Until now you have mainly focused on works that have been produced in Germany?

Christoph Blase: For ‘RECORD > AGAIN! - 40yearsvideoart.de – Part 2’ we did, because this was a project on German video art. We focussed very clearly on German works, German language works or works made by German speaking artists. But we also have already a lot of works from the United States. Of course I also know that there are some regions in Europe where there exists at least the same amount of interesting works than what we have found in Germany - if not more. Of course other institutions that collect early videos do have the same problems as the German collections. This could be one of our next projects.

PACKED: And it could also contextualise the German work?

Christoph Blase: Yes.

PACKED: Do you have works in the ZKM collection that can never be shown again because of certain technical problems?

Christoph Blase: Yes, but this mostly concerns early interactive media artworks of the nineties. There we have works that entail big problems because there doesn’t exist good documentation on them, or even does exist no documentation at all. We did not yet succeed in making a simulation of these works on modern hardware. Until now we do not know whether we will be able to show them again.

PACKED: Is because you do not really know how these artworks functioned or what they "were doing"?

Christoph Blase: We know how these interactive media artworks functioned but unfortunately the equipment is no longer working. They were written in a language that was used by let us say 500 people in 1992 and that was subsequently already completely forgotten in 1994. We know maybe five out of the 500 people: two of them have already died, two others have become in the meantime directors somewhere and they probably do no longer really care and the remaining last one is very expensive and can’t give a guarantee that he will succeed in transferring the artwork. For the early works sometimes documentation doesn’t exist. There are also several problems with a big work that has a room full of interactive stuff. It only concerns a few works, but with these ones there will be big problems.

PACKED: Does this mean that you have always found a solution for the video works?

Christoph Blase: Yes, until now we have always found a solution.

PACKED: Is the situation more problematic for the early computer works?

Christoph Blase: Indeed, at the moment the situation is a little bit problematic for the early computer works, But on the other hand, in the digital world - with all the knowledge that exists about digital works - people are also much more aware of this problem. Furthermore there is growing number of collectors, museums, other institutions and companies that are busy to reconstruct digital data and documents. There is also a growing amount of documentation. I think that the situation will remain problematic for a while but that the problem will also be solved in let’s say twenty years from now. Perhaps one day it will be possible to study the history of computer programming and ‘historical programming’. You will have the possibility to learn all the early languages for computers from the fifties, sixties and seventies. As a result of this there will be specialists. They will probably be very expensive, but they will exist.

PACKED: What are your expectations for the future? We can go on collecting old equipment and making it work again for a certain time, but at one point in the future this is a battle that will also be lost. Or not?

Christoph Blase: Yes or no, that is the big question. Two years ago Johannes Gfeller organised a conference in the framework of his exhibition ‘Reconstructing Swiss video art from the 1970s and 1980s’48 and this question also came up during this conference. Johannes and I had more or less the same opinion on this (laughs). For the next fifty years – and by the end of this period we will all be very old or already dead – we can solve the problem by collecting CRT tubes, refurbishing equipment and so on and in the meantime a generation of specialists on old media technologies will arrive. They already exist for other fields, like for instance for old cars – oldtimers - where you already have different kinds of specialists. There will be specialists for old electronic equipment too.

PACKED: Can we imagine that for example somebody will start producing CRT tubes again?

Christoph Blase: Yes, I wanted to come to this point. For the moment the production of CRT tubes has stopped all over the world, but I am sure that in ten years time there will be a new production of CRT tubes. I do not know which type of CRT will be produced, but there will be a production of CRT tubes. Maybe you will have to pay 1.000 Euros for them, but you will be able to get them if you really want to.

PACKED: Is there a good reason to believe that even without a new production, we can go on for another fifty years or even longer because of the development of new knowledge and ’new old technology‘?

Christoph Blase: Yes, you have to keep in mind that the development of video art and the development of this kind of black and white and colour monitors took place in the sixties and the seventies of the last century. During this period – like during the twenties - a lot of things happened on a societal as well as on a technical level. I think this period will always be in the picture for let’s say the next two hundred years. There will always be a certain interest to renovate the things from that time and show them in a museum context. Of course every ten years some stuff will disappear, but I think that there will remain a certain stock forever. It is the same with the old machines from the twenties: old projectors, cameras, etc. We still have them. We have film museums. We have institutions that hold collections of technical stuff from the beginning of the last century.

Footnotes

1. The documenta is an important exhibition of modern and contemporary art which now takes place every five years in Kassel, Germany. It was founded by artist, teacher and curator Arnold Bode in 1955 as part of the Bundesgartenschau (Federal Horicultural Show) which took place in Kassel at that time. The curator of documenta 5 was Harald Szeeman who invited and presented works of Bruce Nauman, Joseph Beuys, Joseph Thek, Vito Acconci, Joan Jonas, Rebecca Horn, etc. See also: http://www.documentaarchiv.de/documenta/documenta-5.html

2. The Akai 1/4 inch is a videotape recording format produced by Akai Electric LTD in Tokyo in Japan. The portable system with its camera, came with a small removable video monitor and an optional RF (radio frequency) modulator to enable the use with a television set.

3. VidiPax was one of the largest magnetic media restoration, migration, and encoding company in the world, with offices in the United States and Canada.VidiPax specialised in the restoration and remastering of neglected, damaged or deteriorating video, film, audio, and data media. The company has changed its activities in 2009 and is today no longer restoring videotapes.

4. Digital Betacam or DigiBeta is a digital version of the Betacam tape format. For a very long time it has been considered by television and other audiovisual archives as a good archival format because there is no generational loss between two copies. Since it seems that the current technological evolution will result in massive tapeless archiving, it is expected that also digital Betacam will disappear as an archival format.

5. MPEG-1 is a standard for lossy compression of video and audio. It is designed for half screen size (352x288 pixels), and to compress digital video and down to 1.5 Mbit/s (26:1 and 6:1 compression ratios respectively) which results in a moderate quality. It was basically designed to allow moving pictures and sound to be encoded into the bitrate of a Compact Disc. It is used on Video CD, SVCD and can be used for low-quality video on DVD Video. It was used in digital satellite/cable TV services before MPEG-2 became widespread.

6. U-matic is an analogue video format developed at the end of the 1960s and consisted of a ¾ inch magnetic videotape in a cassette. It is the forerunner of the analogue Betacam. The first models of U-matic players and recorders like the SONY VO-1600 or the VP-2030 had their cassette loading system on top. The more recent models have a front-loading system.

7. Sticky-shed syndrome is a condition whereby a tape binder - which hold the iron oxide magnetisable coating to its plastic carrier - has deteriorated to such a degree that it lacks sufficient cohesive strength so that the magnetic coating sheds on playback. The shedding of particles causes a dropout of the video signal on video tapes.

8. Tape baking is a process that is used to restore magnetic tapes like audio cassettes and video tapes that have begun to go through a chemical breakdown due to age and suffer from sticky shed syndrome. Baking a tape consists in putting the tape for a certain duration in a specialised oven, generally at a temperature between 40°C and 60°C max.

9. ½” open reel is an analogue video format introduced in 1965. The ½-inch tape is not inside a cassette but on an open spool. The tapes were used in combination with the first portable video recorders and were widely used by artists, lecturers and activists. Broadly speaking, there are two categories of ½” open reel: CV (Consumer Video/Commercial Video) and AV (EIAJ Type 1). Although the tapes look identical, the players are not compatible.

11. Chistoph Blase refers to a Sony factory that created in 1984 and located in Pontonx-sur-l'Adour, in the South-West of France. This factory was specialised in tape manufacturing and also offered transfer services for open-reel video formats. It was closed in 2009 due to the end of video tape production in France by Sony because of the progressive obsolescence of magnetic tape as a carrier.

13. QuickTime is a multimedia framework developed by Apple. It supports a large number of formats for digital video, media clips, sound, text, animation, music and interactive panoramic images. Here Christoph Blase refers to MOV, a special video format for the Quicktime player. It is available for both Mac OS and Windows operating systems.

14. A compression/ decompression (sometimes coder/decoder) algorithm or scheme that reduces the volume of bits necessary to store a data object such as an image file (compression) but that allows the reconstruction of the compressed data into a usable format for display, processing, etc. (decompression). There are many different codecs, and they are often used to minimize file transfer time in order to optimize images or data for Web use.

15. Data compression means representing digital data using fewer bits than the original. Because video files tend to be large, they usually use (lossy) compression. In lossy compression, the compression is not exactly reversible because part of the data is lost. Digital archiving requires uncompressed or lossless compressed files.

17. Final Cut Pro is a professional non-linear video editing software developed by Macromedia Inc., and since the end of the 1990's a by Apple Inc.

18. Linear Tape-Open (or LTO) is an open format developed in the late nineties for storing data on magnetic tape.

19. The Moving Picture Experts Group (MPEG) is a working group of experts that was formed by the ISO to set standards for audio and video compression and transmission. The MPEG standards are an evolving series, each designed for a different purpose.

20. Montevideo was founded by René Coelho in 1978 in Amsterdam. It quickly had a large selection of works available for rental, of artists such as Bill Viola, Gary Hill, Shelly Silver and Gabor Body. In 1993, Montevideo merged with Time Based Arts, a video distributor founded in 1983 by the Association of Video Artist. Their respective work is continued under the new name of Netherlands Media Art Institute, Montevideo/Time Based Arts.

21. Ulrike Rosenbach (° 1943, Bad Salzdetfurth) is a pioneer and an important figure of video and performance art in Germany. In her so-called video live actions, she exposes patterns of female identity construction and develops strategies of self-determination. See: http://www.ulrike-rosenbach.de

22. Brionvega is an Italian electronics company, established in Milan in 1945, now located in Pordenone, Friuli-Venezia Giulia, Italy. Brionvega is famous for its radio and Television born from the collaboration with well-known design firms. See: http://en.wikipedia.org/wiki/Brionvega

23. Wolf Khalen (° 1940, Aachen) is a German artist working with a.o. photography (since 1956), painting, drawing and printing (since 1960), video (since 1969), sound (since 1970), performance (since 1968), architecture (since 1972) and ethnological documentary video (since 1985), Since 1982 he has been a professor of intermedia art at the Technical University in Berlin. He is also founder of the Videoforum Berlin (1970/71) and ADA I and II (Aktionen der Avantgarde, together with Wolf Vostell and Jörn Merkert) in 1973 and 1974. See: http://www.wolf-kahlen.net/museum/

26. Johannes Gfeller is a professor in the Department of Conservation and Restoration at the Hochschule der Künst HKB, Bern(Switzerland). Since 2002 he is also in charge of the research project AktiveArchive.

28. This exhibition was shown at the ZKM in Karlsruhe from July 17th to September 6th, 2009, at Ludwig Forum in Aachen from September 18th to November 15th 2009, at the Kunsthaus in Dresden from November 28th to February 14th 2010 and at the Edith-Ruß-Haus für Medienkunst in Oldenburg from February 26th to April 5th 2010.

30. A capacitor (formerly known as condenser) is a passive electronic component consisting of a pair of conductors separated by a dielectric (insulator). When a potential difference (voltage) exists across the conductors, an electric field is present in the dielectric. This field stores energy and produces a mechanical force between the conductors. The effect is greatest when there is a narrow separation between large areas of conductor, hence capacitor conductors are often called plates. Practical capacitors are available commercially in many different forms. The type of internal dielectric, the structure of the plates and the device packaging all strongly affect the characteristics of the capacitor, and its applications.

31. THT stands for ‘Transformateur Haute Tension’. It is the French word for ‘High Voltage Transformer’, an essential part of a Cathode Ray Tube. Its main function is to ensure a voltage around 25 Kilovolt for colour monitors or color TVs and 15 Kilovolt for black and white televisions and monitors.

32. Bang & Olufsen is a Danish company that designs and manufactures audio products, television sets, and telephones. It was founded by Peter Bang and Svend Olufsen in 1925. Products by B&O are often of different and distinctive design when compared to other manufacturers. B&O hires designers rather than directly employing them in the company. See: http://www.bang-olufsen.com/

33. Dan Flavin (1933, Jamaica, New York – 1996, Riverhead, New York) was an American minimalist artist famous for creating sculptural objects and installations from commercially available fluorescent light fixtures.

34. NTSC (National Television Systems Committee) is the American standard for the video colour system. It uses 525 picture lines that are scanned at a speed of 30 images per second. The European standard PAL (Phase Alternate Line) uses 625 pictures lines that are scanned at a speed of 25 images per second.

35. Isopropyl alcohol (also propan-2-ol, 2-propanol or the abbreviation IPA) is a common name for a chemical compound with the molecular formula C3H8O. Isopropyl alcohol is produced by combining water and propene. It is widely used to clean electronic components such as tape heads in video and audio players.

38. Dan Graham (° 1942, Urbana, Illinois) is a conceptual artist now working out of New York City. He is an influential figure in the field of contemporary art, both a practitioner of conceptual art and an art critic and theorist. His film and video works address the questions of time and space. Dan Graham made a work called ’Time Delay Room‘ in 1974 that had several versions. See: http://www.eai.org/artistBio.htm?id=403

39. DDR stands for Deutsche Demokratische Republik. It was the socialist state established in 1949 in the Soviet zone of occupied Germany and in the East Berlin portion of the Allied-occupied capital city.

41. Founded in 1969 by Frank Gillette, Michael Shamberg, and Ira Schneider among others, Raindance was a self-described "countercultural thinktank" that embraced video as an alternative form of cultural communication. The name "Raindance" was a play on words for "cultural R & D" (research and development). Influenced by the communications theories of Marshall McLuhan and Buckminster Fuller, the collective produced a data bank of tapes and writings that explored the relation of cybernetics, media, and ecology. From 1970 to 1974, Raindance published the seminal video journal Radical Software (initially edited by Beryl Korot and Phyllis Gershuny), which provided a network of communications for the emerging alternative video movement, with a circulation of 5,000. In 1971, Shamberg wrote Guerrilla Television, a summary of the group's principles and a blueprint for the decentralization of television. In 1976, Raindance members Ira Schneider and Beryl Korot edited Video Art: An Anthology, one of the first readers on video art. The original Raindance collective dispersed in the mid-70s; the nonprofit Raindance Foundation continues to exist today. See: http://www.vdb.org/artists/raindance-corporation

42. Radical Software is a historic video magazine that was started by Beryl Korot, Phyllis Gershuny, and Ira Schneider and first appeared in the Spring of 1970, soon after low-cost portable video equipment became available to artists and other potential videomakers. See: http://www.radicalsoftware.org/e/index.html

47. Ira Schneider is a video artist (° 1939, New York, NY in), living and working in Berlin since 1993. He was a pioneer of video in the late 1960s and early 1970s. In his work with video installation and single-channel tapes, he explored the manipulation of time, interactivity and simultaneity as formal and conceptual devices. He was co-founder, publisher and one of the editors in chief of the magazine Radical Software (1970-1974), as well as president of Raindance Foundation (1972 to 1994), director of the TV show Night Light TV (1980-1992), and Associate Professor at the Cooper Union School of Art, New York (1980-1992). In 1976 he published ‘Video Art - an Anthology’ together with Beryl Korot. See: http://www.ira-schneider.com/artist/index.html, http://www.eai.org/artistBio.htm?id=401 and https://en.wikipedia.org/wiki/Ira_Schneider